Chemical vapor deposition is but one process of providing thin films on semiconductor wafers. It is a favored deposition process in many respects, principally because of its ability to provide highly conformal layers even within deep contacts and other openings. By way of example only, one example prior art chemical vapor deposition technique for depositing TiN is by a low pressure deposition at a pressure of less than 1 Torr. Specifically, an example is the reaction of a titanium organometallic precursor of the formula Ti(N(CH.sub.3).sub.2).sub.4, named tetrakisdimethylamidotitanium (TMAT) and ammonia in the presence of a carrier gas react according to the following formula: EQU Ti(NR.sub.2).sub.4 +NH.sub.3 .fwdarw.TiN+organic by-products
Organometallic compounds contain a central or linking atom or ion (Ti in TMAT) combined by coordinate bonds with a definite number of surrounding ligands, groups or molecules, with at least one of which is organic (the (N(CH.sub.3).sub.2 groups in TMAT). The central or linking atom as accepted within the art may not be a "metal" in the literal sense. As accepted within the art of organometallic compounds, the linking atom could be anything other than halogens, the noble gases, H, C, N, O, P, S, Se, and Te.
By way of example only, silicon would be one such atom which is not a "metal" in the literal sense, yet which can constitute the linking "metal" of an organometallic compound. It would be desirable to develop processes which utilize silicon organometallic precursors as sources for silicon in producing or providing layers of elemental silicon or silicon-containing compounds on semiconductor wafers. For example, silane (SiH.sub.4) is the principal source gas today utilized in semiconductor wafer processing for depositing silicon layers. Silane is an extremely unsafe gas, being very toxic and subject to spontaneous combustion when exposed to air. Accordingly, it would be desirable to develop other silicon sources for depositing silicon-containing layers on a semiconductor wafer.
It would also be desirable to develop alternate source of elements from organometallic precursors for chemical vapor deposition processes in semiconductor wafer processing.